An infrared focal plane array (FPA) is an imaging sensing apparatus that includes an array of pixels capable of detecting photons in the infrared spectrum. The pixels of infrared FPAs may be formed of a material that is sensitive to infrared radiation, such as indium antimonide (InSb), Mercury Cadium Telluride (MCT), quantum well materials, such as gallium arsenide and aluminum gallium arsenide, or other infrared-sensitive detector materials. In quantum well infrared photodetectors (QWIP), alternating layers of semiconductor materials are stacked between electrical contacts. QWIP devices are photoconductive devices in which electric fields normal to the direction of propagation of the infrared radiation excite electrons in low energy wells of the quantum well material to generate a photocurrent. The quantum well stacks are then bonded to a read-out circuit that receives the photocurrent signals generated by the individual quantum well stacks. A plurality of quantum well stacks act as pixels that may be used to generate an infrared image.